Snapchat, Facebook, Twitter and Pandora execs weigh in

A quartet of executives from Facebook, Snapchat, Twitter and Pandora gave advertisers tips on how to reach millennials during a panel at ZenithOptimedia Group's Mobile Day in New York on Tuesday.

Marketers are constantly working multiple social media platforms and tweaking digital ads to target elusive millennials—adults ages 18 to 34 who don't respond to traditional advertising and are increasingly "cutting the cord." But instead of focusing on how young adults are turned off by ads, the speakers suggested spending more time analyzing how they use digital media, and then building marketing strategies around it.

"When we think about millennials, we don't think of them as a segment," said Trevor Johnson, director of Facebook's global agency team. "Millennial behavior is a thing that is really driving social and technology behavior going forward."

Here are four interesting insights the digital players revealed.

1. Get local

Steve Hwang, director of operations and strategy at Snapchat, said brands should think "local" when targeting millennials.

Granted, that's a sales pitch for his company's Live Story feature, which curates streams about nearby events that brands can buy full-page placements in. But the bigger idea is that Snapchat's core group of 18- to 24-year-olds hate feeling like they're being marketed to. Instead, they want to watch videos and look at photos their friends are sharing.

That approach is completely different than how brands use Facebook and Twitter to grow followers, a point Hwang later used as a jab against Facebook.

"Authenticity is really important, and I don't mean in terms of pretending to be [someone's] Facebook friend," Hwang said. "There's a ton of opportunity for brands to be involved on a more local level in the real world."

2. Less is more with video

It's no surprise that autoplay video has taken over Facebook, but that doesn't mean brands are building the right type of social clips for the platform.

Facebook's Johnson advised the room of brands and agency execs to make four-, eight- and 10-second videos that grab young people's attention in a news feed. Once people tap on a video, the sound automatically kicks in, which helps hook them to watch longer clips.

"You have maybe the first three seconds to stop people in their feeds to get them with a piece of content," explained Johnson. "After that, they can either watch five seconds or 10 minutes."

3. Find social's new celebrities

Vine stars are hotter than Hollywood A-listers for millennials, said Stephanie Prager, agency development lead at Twitter.

So those are the people that brands should try to emulate or work with when posting videos, photos and GIFs to the microblogging site. And with the acquisition of social talent agency Niche earlier this year and the launch of live-streaming app Periscope, Twitter is likely to make influencer marketing a bigger part of its pitch to advertisers in the coming months.

"We see these influencers with followers and a social graph that is far bigger than any celebrity out there," Pranger said.

4. Data-backed creative

Despite all the talk about mobile's lack of creative, Pandora's svp of consumer packaged goods sales and strategy, Tamara Bedrosian, argued that data should determine what an ad looks like.

For example, women ages 18 to 34 like to listen to YouTube violinist Lindsey Stirling on Pandora. They're also overwhelmingly listening to her from the music-streaming company's app (80 percent of Pandora's 80 million active users listen on mobile). Those nuggets of information can shape a campaign and determine if it should run on mobile or desktop.

"We don't go out with mobile-first or mobile-only strategies," Bedrosian said. "Tailor your creative message to the environment and mindset."